Patterns of acoustical activity of bats prior to and 10 years after WNS on Fort Drum Army Installation, New York

Tomás Nocera; W. Mark Ford; Alexander Silvis; Christopher A. Dobony

doi:10.1016/j.gecco.2019.e00633

Home/Archive/USGS

USGS · 70223248

Patterns of acoustical activity of bats prior to and 10 years after WNS on Fort Drum Army Installation, New York

Tomás Nocera·W. Mark Ford·Alexander Silvis·Christopher A. Dobony

View original source ↗Export metadata ↓

Abstract

Previous acoustic surveys, netting, and count data have shown that overall bat activity patterns have shifted among most species between pre- and post-white-nose syndrome (WNS) years in much of North America where WNS has occurred. However, the significance of these changes is based on the species-specific susceptibility to WNS. We used acoustically recorded echolocation passes obtained at Fort Drum, New York to describe changes in bat activity pre-WNS (2004–2007) to post-WNS (2008–2018). We examined seasonal and yearly changes in bat activity as they relate to the presence of WNS at hibernacula near (<25 km) Fort Drum. A priori , we expected that overall activity for communal hibernating species would be less in years following WNS, and migratory bats or those hibernating bats that are less affected by WNS would show no response or a positive response, due to niche relaxation/competitive release. Our results indicated both an overall and seasonal decrease in activity for Myotis spp. post-WNS. For WNS-susceptible species, our results reflect the high level of mortality in regional winter hibernacula post-WNS and possibly variable reproductive effort and recruitment thereafter. Although migratory bats did show increases in post-WNS activity throughout the summer, we found little evidence that community displacement was occurring on a nightly level by any species. The continuous spread of WNS across North America has had strong negative effects on bat populations of affected species, and our research identifies how individual species (both impacted and non-impacted) respond to WNS.

Explore related subjects

Global Ecology and Conservation Article

Source-reported bounding extent: 43.98688630934305° to 44.268804788566165° latitude; -75.8660888671875° to -75.36895751953125° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Tomás Nocera, W. Mark Ford, Alexander Silvis, Christopher A. Dobony. 2019. Patterns of acoustical activity of bats prior to and 10 years after WNS on Fort Drum Army Installation, New York. https://doi.org/10.1016/j.gecco.2019.e00633

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Key considerations for decision makers and stakeholders when identifying source populations for conservation translocations of fishes

Conservation translocations are undertaken to increase the viability of imperiled organisms and/or restore ecosystem functions or processes. A key step in the conservation translocation process is to decide which source or founder population is most likely to lead to translocation success. Existing guidance to inform this decision includes a variety of considerations, but few documents focus solely on this step. Furthermore, despite the importance of stakeholder engagement to long-term conservation success, guidance for selecting source populations rarely describes approaches for stakeholder inclusion. Herein, we undertook a literature review for fish conservation translocations and summarized key considerations (e.g., genetics, habitat, life history, effects on source or recipient populations and ecosystems, logistical) to be used when selecting candidate source populations. We describe the importance of including stakeholders and recommend that decision makers coproduce the source population decision with them. We propose a structured expert judgment approach to assess the probability that specific aspects of these considerations could be achieved for each candidate source population. Finally, we recommend synthesizing results of the expert judgement process to enable decision makers and, ideally, invited stakeholders to choose which source population(s) based on their previously identified fundamental objectives. Although we developed this approach for fishes, it could be used for other conservation translocation efforts where stakeholder involvement and synthesis of support for different source populations are deemed valuable in the planning process.

Global Ecology and Conservation↗

USGS2026

Hakalau’s moving castle: How climate change and restoration are shifting an island fortress for forest birds

Hakalau Forest Unit of the Big Island National Wildlife Refuge Complex (hereafter, Hakalau) protects the largest area with the highest endemic forest bird diversity in Hawaiʻi, including four federally listed species. Hakalau’s higher elevation montane forest provides refuge from avian malaria ( Plasmodium relictum ), a primary driver of Hawaiian honeycreeper extinctions. However, recent declines in Hakalau’s birds at lower elevations could indicate that conditions have become suitable for disease vector Culex quinquefasciatus . We evaluated the statuses of Hakalau’s bird populations in the context of recent climatic changes using new survey data from point-transect distance sampling, producing abundance estimates from 1999 to 2024. We stratified our analysis across four elevation ranges (<1500 m, 1500–1700 m, 1700–1900 m, and >1900 m) and assessed trends for each species using state-space models (SSMs). We constrained population trajectories to be biologically realistic by incorporating population dynamic models within the SSMs. We observed highly species-specific abundance trends below 1500 m, predominantly stable to upward trends within 1500–1700 m, stable trends within 1700–1900 m, and upward trends above 1900 m. Declines in Hawaiʻi ʻamakihi ( Chlorodrepanis v. virens ) and endangered ʻakiapōlāʻau ( Hemignathus wilsoni ) abundance coincided with lengthening warm seasonal temperatures indicative of shrinking disease-free habitat below 1700 m. Above 1900 m, however, increases in nearly all species indicate that reforestation has likely restored disease-free habitat since 1999. While most species were stable to increasing overall, surveillance for mosquitoes and disease at lower elevations, documenting changes in habitat, and continuing bird population monitoring can help to gauge their long-term persistence at Hakalau.

Hawaii↗

USGS2026

Status assessment of peregrine falcons in North America using integrated population models

Species status assessments require an understanding of underlying population dynamics and important drivers of species demography. Large-scale assessments can be difficult due to challenges collating data obtained through different methods and different sources at multiple scales. Integrated population models (IPMs) provide a unified framework to combine multiple data sources and jointly estimate population parameters over a large spatiotemporal scale. We developed separate IPMs to estimate abundance and demographic rates for a northern (NMP) and southern (SMP) management population of peregrine falcons ( Falco peregrinus ) in North America from 2008 through 2019 (SMP) and 2020 (NMP). An outbreak of highly pathogenic avian influenza (HPAI) starting in 2021 led us to extend our modeling effort to assess its impact on these management populations by updating both IPMs using index data of population size through 2024 in a predictive framework. Survival probabilities differed drastically between first-year and after-first-year individuals in both management populations. After-first-year survival was nearly identical between the NMP and SMP, but first-year survival was lower in the SMP. Mean productivity was significantly lower in the NMP compared to the SMP, whereas the probability of breeding was similar in both management populations. Estimated total abundance for the NMP was substantially larger than the SMP, representing most of the North American peregrine population. Population growth was positive for both management populations, albeit at a slower rate for the NMP. The NMP declined from 2017 to 2018 coinciding with a drop in 2018 estimated productivity. When we extended the IPMs with updated count data through 2024, the NMP slightly declined but estimated abundance remained above levels at the start of the time series analyzed. The SMP grew at a similar rate to that predicted during the period informed by demographic data. We did not detect a continental-scale change in population size or trajectory in either management population associated with the arrival of HPAI in 2021. Further monitoring can support determination of whether the declines in the NMP were temporary, can enhance understanding of the underlying mechanisms, and can be used to guide the conservation and management of the peregrine falcon population in North America.

North America↗